Outbuilding less than 30m2 with a toilet

[JT101]

Hi guys

Am planning on building a garden room on heavy clay soil in SE london.

Am keeping to 30m2 internally as I want to avoid building control if I can. Building control are virtually impossible to get hold of right now, but from the very brief e-mail I recieved, they want 2m deep piles or a raft foundation with all calcs etc if they get involved which is a lot more expense and delays. (FYI I normally use some form of shorter pile concrete or metal screws and have always been solid.)

Two questions:

1) If I add a toilet & basin, do I still have to go through building control?

2) And if I do, will it just be for those parts rather than the structure, and foundations?

Only thing I can find is here: Does my new outbuilding need building regulations approval? | LABC which suggests A) Electrics can be done through electrician, B) drainage isn't notifiable. C) The only possibly notifiable work is hot & cold water supply which would come from the house. But the wording is confusing to me.

Thanks

 

[big-all]

doesnt it say something like " between 15 and 30 must be made substantially off non-combustible materials iff within 1 metres" ??

 

[big-all]

"If the floor area of the building is between 15 square metres and 30 square metres, you will not normally be required to apply for building regulations approval providing that the building contains NO sleeping accommodation and is either at least one metre from any boundary or it is constructed substantially of non-combustible materials."
https://www.planningportal.co.uk/info/200130/common_projects/43/outbuildings/2

 

[oldbutnotdead]

Re your loo and basin- provided you've kept the correct side of the other conditions (no sleeping, substantially non-combustible construction etc etc) then yes they'll check out your loo/basin and waste pipes and only them. If you're on heavy clay they'll prob suggest/allow gutters to drain into the foul drainage as well (soakaways don't work on clay) if there isn't separate surface water drainage already connected to the house.

 

[JT101]

Thanks oldbutnotdead. No sleeping accommodation, and our facia is 2m clear of the boundary so we have no requirements for fireproof materials.

LABC website suggests drainage isn't notifiable only electrics and water. I don't fully understand why there is a separate website for Local Authority Building Control from the Planning Portal or Council websites, but if it says it on their site, then this must be the rule:

"The extension of any existing drainage system to serve the exempt detached building (less than 30m2), in which case the extended drainage must comply with Parts H1 – Foul drains; H2 – Wastewater treatment and cesspools; H3 – Rainwater drainage, where applicable however the drainage is part of the exemption and so doesn't have to be notified to the local authority."

It's the water bit I'm not so sure on:

"The installation of cold or hot water supplies from a source shared with or located inside any building other than a building or extension of a kind also described in Schedule 2, in which case the work must comply with Parts G1 – Cold water supplies and G3(2) & (3) Hot water storage systems of the building regulations - and is notifiable work."

I think it means if I connect to the house water supply then it becomes notifiable work. In which case this is the only part that is notifiable (any electrics would be self certified).

 

[oldbutnotdead]

Interesting...best read up on the bits and bobs about water supply hadn't i- BCO up here was only concerned with where the water from the gutters on the garage was going-again clay so had to link to house drainage, at which point I put a loo & washbasin in the shed as well. You'll have to dig a trench for the power cable, water has to be min 750mm deep iirc, sand bed for pipe, duct it through any masonry...

 

[charliegolf]

Interesting...best read up on the bits and bobs about water supply hadn't i- BCO up here was only concerned with where the water from the gutters on the garage was going-again clay so had to link to house drainage, at which point I put a loo & washbasin in the shed as well. You'll have to dig a trench for the power cable, water has to be min 750mm deep iirc, sand bed for pipe, duct it through any masonry...

Really not trying to be clever, but if <30 sqm is outside BR remit, why is a BCO getting involved?

 

[oldbutnotdead]

Really not trying to be clever, but if <30 sqm is outside BR remit, why is a BCO getting involved?

Cos the main structure is exempt (due to its size) but bits and bobs (water supply much to my surprise) are apparently notifiable

 

[JT101]

Couldn't have said it better myself. I will try and get a definitive answer from BC

 

[JT101]

I can report back that this was a stressful and annoying experience. Partly because I was given the wrong information and partly through not being able to speak to anyone.

I will just talk through the process of going through building control for anyone interested:
Certain projects or work is deemed as "notifiable", i.e. you must "notify" the building control department of your local council. An example like in my case is when an outbuilding has more than 30m2 internal floor area.

Building regulations are a set of rules designed to ensure that buildings are built to a certain standard, which principally I fully agree with, to prevent shoddy work and unsafe construction. The building control department enforces this through inspections. Ultimately they will or won't sign off on the work and issue a certificate.

When you seek building control approval, the first step is to make a Building Notice application (limited info required e.g. often a hand sketch is sufficient, only have to wait 48hrs before commencing work and relatively cheap. It is meant for minor works requiring a quick start date, but requires more inspections owing to the lack of info provided upfront). Full plans is essentially the opposite. More expensive, more detailed but requires less inspection.

You can build what you like, however you like, whenever you like, and building control cannot stop you or hold you up. However you don't seek building control approval when you should, and they are alerted e.g. by a disgruntled neighbour, you the builder or the landowner may be forced to tear down or modify any works if you cannot prove you have built to the building regulations. By not having a certificate from building control, you may cause issues when selling your property. The new owners may have to take out building insurance, pay a surveyor etc which is obviously a negative.

So by and large, it is a good thing and should be sought.

However, since the pandemic, I have discovered that all officers are working from home, are super busy and virtually impossible to contact. They won't give out a phone number, only contactable by email, take ages to respond and will only visit site if they absolutely have to.

In my case they also gave out incorrect information. As I mentioned above, reducing the internal floor area to 30m2, should have meant the building and foundations are not controllable or notifiable. Only the services i.e. water, electrics and plumbing.

But I was told by the officer, because it has a toilet, the whole building must follow building regs. I employed a structural engineer for around £1000 to design new foundations, which we costed at close to £10000. This was a perimeter trench foundation 1m deep with a reinforced slab on top. Previously we had quoted £2500 for screw piles or similar.

I disputed this with the inspector citing their own LABC website which I linked above. (The LABC website is the body that trains the inspectors who work for the council). It dragged on so long, we were losing money and had to pull off the job.

Eventually I went to his senior since i couldn't even get a response from him. He agreed with me. Not only that, we had been overcharged for the fee. Paid £450 instead of £273.

So now, after all the anguish and stress, I have a structural engineer i didn't need and am back to square one.

Lesson learned. DO NOT get building control involved if you can avoid it, and if you do, read them their own literature! And stick to your guns.

 

[jlaw]

I can report back that this was a stressful and annoying experience. Partly because I was given the wrong information and partly through not being able to speak to anyone.

I will just talk through the process of going through building control for anyone interested:
Certain projects or work is deemed as "notifiable", i.e. you must "notify" the building control department of your local council. An example like in my case is when an outbuilding has more than 30m2 internal floor area.

.......................................

Lesson learned. DO NOT get building control involved if you can avoid it, and if you do, read them their own literature! And stick to your guns.

I'm still confused!

So did you have to notify building control for:

a) the building
b) water
c) electrics
d) drainage
e) none of the above?

 

[JT101]

a) No
b) Yes
c) Yes, but this is self notifiable by the electrician. i.e. he can sign it off if he is qualified, and BC don't need to inspect.
d) Yes. Although it is not required, they say that they do it anyway because of so much bad drainage being installed.

 

[RonnyRaygun]

I employed a structural engineer for around £1000 to design new foundations, which we costed at close to £10000. This was a perimeter trench foundation 1m deep with a reinforced slab on top. Previously we had quoted £2500 for screw piles or similar.

Out of interest, why did your structural engineer want to go with trench fill and reinforced slab rather than screw piles? Seems to me that for a lightweight structure such as yours screw piles would be a very economical solution - less excavation, less muck away, no big pour of concrete. It's even simple to install either a steel or timber ring beam to the top of the piles and completely avoid the requirement for concrete on the build. Much more environmentally friendly and designed properly every bit as stable as a concrete foundation.

Too many SEs go with concrete foundations as it's what they know and have experience of, but a screw pile specialist would design the foundations for you. If the foundations aren't in it would be worth contacting some screw piling companies as it'll almost certainly work out much cheaper than concrete (as you said above).

 

[^woody^]

However, since the pandemic, I have discovered that all officers are working from home, are super busy and virtually impossible to contact. They won't give out a phone number, only contactable by email, take ages to respond and will only visit site if they absolutely have to.

In my case they also gave out incorrect information. As I mentioned above, reducing the internal floor area to 30m2, should have meant the building and foundations are not controllable or notifiable. Only the services i.e. water, electrics and plumbing.

But I was told by the officer, because it has a toilet, the whole building must follow building regs.

The main thing to remember is that the national building control service is variable as is any advice given by officers - and this applies to private and council service.

The several authorities around me give out the officers mobile number and email, and you can contact them easily and have been able to throughout the pandemic.

The thing with building regulations generally is that there can be several interpretations of the requirements and different officers can give different opinion. The answer to to that would be to have a set of rigid rules that everyone keeps to, and that would be no good for applicants or builders as things aren't rigid and fixed on site there needs to be flexibility. And officers are there to check work you have done not advise you what to do.

What you should have done is instruct a professional to advise you and deal with the regulations, then you wont have had the problems you had. And part of that advice would have been to construct your exempt building first, and then add the drainage - seeking approval for the drainage/WC element only.